Depression currently affects around one in five people in the UK, with many patients failing to respond to conventional treatments such as cognitive behaviour therapy or anti-depressant medications.
Now, a study in a group of 18-to-25-year-old men carried out by researchers from the University of Technology Sydney (UTS) has found that switching to a Mediterranean diet may help to improve the symptoms of depression.
The team put a group of 72 young men suffering from moderate to severe depression on a diet rich in vegetables, legumes, whole grains, oily fish and olive oil and low in read meat and fast or processed foods for 12 weeks.
They asked the participants to score themselves on the Beck Depression Inventory Scale - a questionnaire frequently used to evaluate patients' moods - at the beginning, halfway through and at the end of the study and also to rate their quality of life over the same intervals.
The participants reported significant improvements on both measures during the course of the study when compared to a control group that were offered befriending therapy - a type of commonly used therapy that involves pairing a patient up with a volunteer for support.
"There are lots of reasons why scientifically we think food affects mood. For example, around 90 per cent of serotonin, a chemical that helps us feel happy, is made in our gut by our gut microbes," said lead researcher Jessica Bayes, a PhD candidate in the UTS Faculty of Health.
"There is emerging evidence that these microbes can communicate to the brain via the vagus nerve, in what is called the gut-brain axis.
"To have beneficial microbes, we need to feed them fibre, which is found in legumes, fruits and vegetables."
The researchers found that the participants had no issues in transitioning to the new diet and that many of them were eager to continue to keep to it once the study had ended.
"We were surprised by how willing the young men were to take on a new diet," said Bayes.
"Those assigned to the Mediterranean diet were able to significantly change their original diets, under the guidance of a nutritionist, over a short time frame.
"It suggests that medical doctors and psychologists should consider referring depressed young men to a nutritionist or dietitian as an important component of treating clinical depression."
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